the water line tile in the pool has been falling off. I got the idea to repair it. so I drained the pool, an inground gunite pool, and found that more tile were loose and ready to fall so I took ALL the tiles off very easy to do by the way. I ordered glass 1"x1" tile on 12"x12" mesh. Now here is where the problem is first the the old tiles came off for a reason why? second no one gives me the same answer on the best way to attach the new tiles to the pool, what to use thinset, mortor, silicon adhesives ??? I can't get two like answers. I live in SC so our summers are hot and our winters can have a few cold nights. I know the glass will not contract and expand like the gunite wall so what to use so that the movement won't break or pop off the glass tiles. Thanks for any help.